The Center is focusing on the assessment of quality, utilization, and economics of primary care and how consumer, provider, management, and structural factors, as well as sources, methods, and levels of payment influence the results. Issues are sought out for which the evaluative process provides a basis initially for considering modification of some aspect of the delivery system, (e.g., use of mid- level manpower) and later for measuring the outcome or change. The Center is moving into a phase in which the emphasis is on highly targeted research projects dependent on multidisciplinary approaches. Studies are to be carried out to determine (a) the utility of an encounter data information system in reviewing process and outcome of ambulatory care; (b) the feasibility of establishing peer review procedures for drug utilization and the effect of such a review procedure on utilization; (c) the health care behavior of populations who utilize different systems of health care and the outcome of care in these subgroups; (d) the relationship of different mixes of manpower staffing to the quality, cost, and acceptability of services provided. These investigations are concerned primarily with four delivery systems affiliated with Johns Hopkins University, two of which are HMO's, one is a clinic in a housing project, and the fourth is an OPD which provides about a half million services per year.